The single-best indicator, or one of the single-best indicators, of a country's prosperity around the world is how does it treat its women.

WHITEHOUSE: President Obama and President Karzai Hold a Press Conference | The White House

Although it would definitely be useful to know your car's fuel mileage (a decline in miles per gallon is a good indicator of potential problems), I'm not dedicated enough to enter every single gasoline purchase.

CNN: Use your Mac to track your money

This is one advantage over the Conference Board's leading economic indicator, which conceals useful information by combining longer- and shorter-term indicators in a single measure.

ECONOMIST: Leading economic indicators